You are just plain wrong about Congress and about the executive branch, but spot on about the president.

The president’s job is to execute the laws of the US, and is laid out clearly in article 2 of the constitution. I’ll go one further, it’s to “faithfully” execute the laws of the US- Article 2, section 1, clause 8.

The Constitution explicitly vests all executive authority in one person - the President. This is done in the “Vesting Clause” of article 2. This means it is the presidents job- alone- to execute the laws. Congress appropriates money for the executive branch to hire people, and Congress may organize the executive branch into departments headed by appointees of the President but approved by the Senate; nothing in that takes away from the President’s sole executive power and responsibility; it just gives him the resources he needs to do his job.

Congress’ powers are strictly enumerated in Article 1 of the Constitution- in fact they are explicitly listed in Article 1, section 8.

You are just wrong about Congressional supremacy. The Constitution is designed to establish 3 co-equal branches of government and a system of checks and balances.

It is absolutely up for debate whether Trump is incorrectly arrogating to himself powers reserved to Congress- the Supreme Court hasn’t ruled on many issues yet where this is the core controversy. It’s widely expected that Trump will ultimately lose at the Supreme Court on his use of tariffs for this reason.

Re: SSA data. It is absolutely the right (and responsibility) of Congress to have hearings on the matter. Their only recourse in response should they not like what they find is to cut off the money (technically they could impeach the president but I think that not even the most generous reading of “high crimes and misdemeanors” by fair minded people would include data handling practices.